I've a part of my lawn which doesn't drain well. I've tried putting in
drainage holes and filling them with sharp sand, but this doesn't seem to
have helped. It also doesn't get much sun because of the neighbouring
conservatory. As a consequence, it ends up with loads of moss and very
little grass. Strangely this is also the part of the garden that I dug up
after the builders left it in a bit of a state.

Does anyone have a suggestion as to how to improve the drainage? I don't
want any expensive solutions involving digging it up and putting in complex
drainage pipes.